Will FITB's full-year 2026 NII come in below the $8.6B guidance floor?

The $8.6B floor assumes the forward curve with 25bp cuts in March and July. The combined entity has 80% floating-rate C&I, making NII highly rate-sensitive. If the Fed cuts more aggressively (4+ cuts vs. 2 assumed), NII could miss the floor. However, FITB has several offsets: 15bps NIM improvement at close (partially from purchase accounting), fixed-rate asset repricing tailwind, and deposit cost reductions from funding synergies. The purchase accounting accretion (8-10bps) is front-loaded and provides a cushion. Standalone FITB generated $6.0B NII; adding Comerica's balance sheet gets the $8.6B floor — this is mostly arithmetic, not growth dependent.

I weight the rate risk more heavily. The Fed's path is genuinely uncertain in 2026. If the economy weakens and the Fed delivers 100bps+ of cuts (vs. 50bps assumed), the impact on 80% floating C&I could be $200-400M of NII compression. The 15bps NIM improvement at close provides some cushion, but 8-10bps of that is purchase accounting accretion that declines over time. The 50% deposit beta from 2025 suggests FITB can pass some rate decreases to depositors, but the lag creates NIM compression before deposit costs adjust. The chronic postponement syndrome also limits loan growth, which compounds rate-driven NII pressure.

The $8.6B floor represents the low end of guidance. Management typically provides conservative guidance — FITB has delivered positive operating leverage and record NII. The floor likely has a margin of safety built in. The question is whether the rate environment could overwhelm even the conservative assumptions. With 2 cuts priced in and the possibility of more, there's meaningful risk. But the $8.6B floor would also benefit from purchase accounting marks, synergy-driven funding cost reduction, and Comerica's commercial loan book contributing more than the minimum expected. I estimate roughly 1 in 4 chance of missing the floor.

The guidance floor of $8.6B is conservative relative to the guidance range ($8.6-8.8B). FITB management has a track record of meeting or exceeding guidance. The primary risk is a more aggressive rate cutting cycle than the 2-cut assumption. However, the merger arithmetic (adding Comerica's ~$80B commercial book) provides a large base that should anchor NII near the low end of guidance even with modest rate headwinds. I give roughly 1 in 5 probability of missing.

I'm less confident in the guidance hold because the rate environment is genuinely uncertain. The forward curve has been consistently wrong about Fed actions for years. If the economy enters recession in H2 2026, the Fed could cut 150-200bps, which would overwhelm the purchase accounting cushion and merger synergies. The 80% floating C&I portfolio is an outsized risk that FITB acknowledged needs hedge management. The wide NII guidance range ($8.6-8.8B) itself reflects management's uncertainty about the rate path.

Balanced view: the merger arithmetic provides a strong NII base, management guides conservatively, and the purchase accounting cushion helps. But rate sensitivity is real with 80% floating C&I. I give roughly 1 in 4 chance, weighted toward the rate risk scenario but acknowledging FITB's hedging capabilities and multiple NII support mechanisms.

Merger arithmetic supports the floor. Rate cuts are the main risk. Conservative guidance has buffer. About 1 in 5 chance.

80% floating C&I is a significant vulnerability. If rates cut more than expected, NII misses. More rate cuts than 2 assumed is plausible.

Balanced probability. Floor is conservative but rate risk is real. Purchase accounting and synergies provide cushion.